Apple Watch Series 3 debuted in September of 2017 but, as is my wont, I'm already thinking about the next version. What will it look like? What new features will it have that pique my fancy?

April 14, 2018: Third-party Apple Watch face rumors once again make the rounds

Ever since Apple Watch debuted with Mickey Mouse on its face, pretty much everyone has dreamt of more open and expansive support. While Apple has added more faces over the years, the company still hasn't added watch faces to the App Store. That may not change for a while, but there also may be infrastructure already in place to allow it one day.

Code found on watchOS 4.3.1 suggests this could change in the future. A component of the NanoTimeKit framework, responsible for the watch faces, implements a developer tools server that's probably designed to communicate with Xcode running on a Mac. One of its methods has a very interesting log message: "This is where the 3rd party face config bundle generation would happen"

Again, don't go getting any hopes up. Beyond it being unclear if Apple will ever surface any third-party watch face functionality, it's unclear how it would be surfaced. We could get nothing. We could get a strict partner program. We could get a highly curated store. Or we could get an open API.

Ming-Chi Kuo of KGI is at it again, this time with a report concerning the next iteration of the Apple Watch. According to Kuo's report, coming via 9to5Mac the Apple Watch Series 4 will launch later this year with a new design, as well as a 15% larger display.

With a launch in the third quarter of 2018, Ming-Chi Kuo says the new watches will have a 15% larger display. All Watches to date come in 38 mm or 42 mm screen sizes.

If it's indeed true that the Apple Watch Series 4 will have both a redesigned chassis and a bigger display, there are questions to be answered. First: how will this redesign impact what we currently think of as the 38mm and 42mm Apple Watches? How big will this redesign be? And, perhaps most importantly: will I have to get all new watch bands to use with the Series 4?

March 18, 2018: Apple rumored to be going all-in on MicroLED for Apple Watch

What comes after CRT, Plasma, LCD, and OLED? According to some, it'll be MicroLED, which offers many of the advantages of OLED but without some of the compromises. And it looks like Apple's already well on its way there.

Apple Inc. is designing and producing its own device displays for the first time, using a secret manufacturing facility near its California headquarters to make small numbers of the screens for testing purposes, according to people familiar with the situation.

The technology giant is making a significant investment in the development of next-generation MicroLED screens, say the people, who requested anonymity to discuss internal planning. MicroLED screens use different light-emitting compounds than the current OLED displays and promise to make future gadgets slimmer, brighter and less power-hungry.

Instead of a single backlight, like iPhones up until iPhone 8, or self-lighting, like iPhone X, MicroLED uses individual LED backlights for each pixel and sub-pixel.

Just like Apple Watch was first to go to OLED, years before iPhone, it could well be first to go MicroLED as well. Previous ruimors suggested it could be as early as this year or next, though with new technologies — and given how conservative Apple has been with them — only ever expect them when you see them in mature, high-quality form.

February 22, 2018: Apple looking at ways to track Yoga workouts with Watch

Apple's proposal suggests using a heart-rate sensor, a thermometer to measure ambient temperature as well as motion-sensing.

From Apple's filing

A motion sensing module can collect user's motion data. In some embodiments, a hot yoga session can be detected based on measured ambient temperature. In some embodiments, a yoga type can be detected based on the motion data. In some embodiments, an energy expenditure model can be applied based on the determined yoga type.

As always with Apple, patents filed do not products shipped make. But, it'd be great.

December 21, 2017: Apple said to be working on EKG monitor for Apple Watch

Apple is reportedly developing an electrocardiogram (EKG) for upcoming versions of the Apple Watch. The EKG is aimed at allowing doctors to better diagnose problems like arrhythmia or discover stroke warning signs, according to Bloomberg:

A version being tested requires users to squeeze the frame of the Apple Watch with two fingers from the hand that's not wearing the device, one of the people said. It then passes an imperceptible current across the person's chest to track electrical signals in the heart and detect any abnormalities like irregular heart rates. Such conditions can increase the risk of strokes and heart failure and develop in about one-quarter of people over 40, according to the U.S. Centers for Disease Control and Prevention.

No word yet on if this is something for a potential Apple Watch Series 4, or something further down the road.

When's the next Apple Watch going to come out?

There's not a ton of speculation out right now, but if we were betting folk, we might lean toward the Fall season, around the same time as the next iPhone. That would mean a Fall 2018 launch for the Series 4 Apple Watch — on par with what we've heard previously. Not only does that give the company the year to perfect new hardware, but it would continue the Watch's release cycle alongside Apple's most popular product, the iPhone, standardized in 2016 with the release of the Series 2. Given that the Apple Watch requires an iPhone to function, it seems logical to pair the two.

What's it going to look like?

Apple still hasn't released official numbers on how well the Watch and its various lines are doing, but I'd expect both the Sport and steel Apple Watch casings to show up in Series 4 — though we might see a new anodized color option in the Sport line. (Perhaps a Product RED Sport?)

We also might see a new Apple Watch Edition, replacing the Ceramic model. (Personally, I'm rooting for meteorite.)

What about a round version?

While I'd love to see some variation on Apple Watch styling, a round Apple Watch would require a round interface; on top of that, to prevent fragmentation, watchOS would have to work on both rounded rectangle and circular Apple Watches. That's a big challenge for the company's software team, and perhaps not one Apple feels up to tackling for 2018.

What sizes will it come in?

Some people like big watches, just like some people like Plus-sized phones, so we won't say never on the prospect of a bigger model; that said, 38mm and 42mm seem to be doing well for the company for now, though, and will probably continue into series 3.

What kind of bands will be available?

Expect new Fall colors for Apple's Sport, Woven Nylon, Classic Buckle, and Modern Buckle, along with a potential new mystery band or two. We might also see new Nike and Hermès colors as well, and perhaps other designers getting into the mix.

As MacRumors noted earlier in 2017, Apple has filed patents for modular bands that could add additional functionality to the watch, including additional battery life, haptics, health sensors, and more, though it's hard to bet on when (if ever) a patented product will see the light of day.

How about the internals?

The S1P and S2 processor powering the Series 1 and 2 Apple Watch gave the original "Series 0" Apple Watch a huge upgrade; the S3 in the Series 3 even more so. An S4 system-in-package for Series 4 should provide a similar boost. Also, the smoother watchOS gets, the better for everyone — I still run into lags here and there, especially on third-party apps.

What about battery life?

As with processor, the Series 2 and series 3 watches both gained big improvements to battery life, with both models now lasting a full 18-hour day — with workouts — without needing a charge. Apple can never stop innovating in this arena, however, especially if it plans to one day allow the watch to sleep tracking (without having to own separate "day" and "night" Apple Watches).

Will Series 4 get full cellular data, decoupling it from the iPhone?

Series 3 brought LTE but only when coupled with an iPhone and some services, like SMS, require the iPhone to be on-network. It's convenient because it means you don't have to get and manage a separate cell number just for your watch, but it also means the watch isn't really an independant LTE device.

So, could Series 4 cut the coupling? Maybe. If Apple can figure out a way to keep it simple.

Any new health sensors?

Health is a huge part of the Apple Watch's message, but right now, the company's somewhat limited in what it can do without FDA approval — and the organization's involvement during development, which could compromise Apple's vaunted security policies.

The current Apple Watch has a pulse oximeter on the rear casing; when pressed against your wrist, it uses a technology called photoplethysmography to measure how fast blood is flowing through your veins. Currently, Apple just uses this sensor for pulse readings, though in theory, the company could also use it to check the oxygen saturation in your blood, or (as suggested by a recent patent uncovered by AppleInsider) identify who's wearing the watch based on your heart patterns.

There are currently third-party apps that do this on the iPhone by having you press your finger up against the rear camera and flash, but they're expressly marked with warnings that disqualify it as "official" testing hardware, and encourage anyone with medical problems to see a doctor. (See my above comment about "FDA-approved and tested.")

The same goes for blood pressure and glucose monitoring. CNBC reported that the blood sugar monitor has made significant progress.

The initiative is far enough along that Apple has been conducting feasibility trials at clinical sites across the Bay Area and has hired consultants to help it figure out the regulatory pathways.

While they would be fantastic statistics for users with blood pressure problems and diabetes, Apple may be better off pairing with third-party Bluetooth devices that are FDA-approved. That's not to say we won't see these sensors in the Series 3 — but if we do, expect to hear about them through the FDA's approval process first.

Additionally, if the company can improve battery life, we may well see the introduction of sleep tracking. There are a few apps (like David Smith's excellent Sleep++) that can do this already on the watch, but they require significant battery use and the ability to charge the timepiece in the morning.

I also wouldn't be surprised to see more information from Apple's chief operating officer and Health spokesperson Jeff Williams on CareKit and ResearchKit; both features have the potential to change patients' lives for the better, and Apple will no doubt be touting the studies — and any new trials — as part of the Watch experience in the Fall.

Will I be able to use my Android phone with the Series 4?

We haven't heard anything to that effect. But if the company wants to make Apple Watch available to the largest group of users, it's a smart move to consider — and there's precedent in Apple Music, iTunes, the iPod, and iPhone. And given that Android Wear watches support the iPhone, there may be a strong business incentive to move in that direction.

Of course, Apple may want to keep the Watch platform-exclusive; depending on the wearable's features, it might be another good way to convert users to iPhone.

Any word on watchOS 5?

A few nibbles here and there, mostly around new sports activities for the Workout app, like Yoga.

Your hopes?

What do you want the next Apple Watch to look like? Me, I'm hoping for at least some of the following:

More health features: An oximeter (to read blood oxygen levels) would be pretty cool, as would a second-generation sensor with better pulse tracking during workouts.

A slimmer case: I wouldn't trade it for battery life, but if anyone could figure out how to make a thinner watch with the same battery tech, it's Apple.

Always-on display: Like a slimmer case, this requires Apple to have its battery needs in check; that said, it's one of my only remaining nitpicks with the current generation of Apple Watch.

Round face: Honestly, I don't know if I actually want this or just want to see Apple's take on it. Either way, round faces are traditionally more flattering to ladies' wrists (though they need to be sized accordingly).

Decorative bands: I'd love a more eclectic, jewelry-style band from Apple. Why not?

Serenity Caldwell

Serenity is the Managing Editor at iMore. She's been talking, writing about, and tinkering with Apple products since she was old enough to double-click. In her spare time, she sketches, sings, and in her secret superhero life, plays roller derby. Follow her on Twitter @settern.